from pypinyin import pinyin, Style


def get_first_letter_pinyin(chinese_str):
    result = pinyin(chinese_str, style=Style.FIRST_LETTER)

    #  摊平数组
    def for_for(a):
        return [item for sublist in a for item in sublist]

    result = for_for(result)
    return "".join(result)
